pinctrl: intel: Add Intel Denverton pin controller support

This driver adds pinctrl/GPIO support for Intel Denverton SoC. The GPIO
controller is based on the same hardware design that is already used in
Intel Sunrisepoint so we leverage the core driver here.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>